litex/misoclib/framebuffer/format.py

122 lines
3.1 KiB
Python

from migen.fhdl.std import *
from migen.flow.actor import *
from migen.bank.description import CSRStorage
from migen.actorlib import spi
_hbits = 12
_vbits = 12
bpp = 32
bpc = 10
pixel_layout_s = [
("pad", bpp-3*bpc),
("r", bpc),
("g", bpc),
("b", bpc)
]
def pixel_layout(pack_factor):
return [("p"+str(i), pixel_layout_s) for i in range(pack_factor)]
bpc_phy = 8
phy_layout_s = [
("r", bpc_phy),
("g", bpc_phy),
("b", bpc_phy)
]
def phy_layout(pack_factor):
r = [("hsync", 1), ("vsync", 1), ("de", 1)]
for i in range(pack_factor):
r.append(("p"+str(i), phy_layout_s))
return r
class FrameInitiator(spi.SingleGenerator):
def __init__(self, pack_factor):
h_alignment_bits = log2_int(pack_factor)
hbits_dyn = _hbits - h_alignment_bits
layout = [
("hres", hbits_dyn, 640, h_alignment_bits),
("hsync_start", hbits_dyn, 656, h_alignment_bits),
("hsync_end", hbits_dyn, 752, h_alignment_bits),
("hscan", hbits_dyn, 800, h_alignment_bits),
("vres", _vbits, 480),
("vsync_start", _vbits, 492),
("vsync_end", _vbits, 494),
("vscan", _vbits, 525)
]
spi.SingleGenerator.__init__(self, layout, spi.MODE_EXTERNAL)
class VTG(Module):
def __init__(self, pack_factor):
hbits_dyn = _hbits - log2_int(pack_factor)
self.enable = Signal()
self.timing = Sink([
("hres", hbits_dyn),
("hsync_start", hbits_dyn),
("hsync_end", hbits_dyn),
("hscan", hbits_dyn),
("vres", _vbits),
("vsync_start", _vbits),
("vsync_end", _vbits),
("vscan", _vbits)])
self.pixels = Sink(pixel_layout(pack_factor))
self.phy = Source(phy_layout(pack_factor))
self.busy = Signal()
###
hactive = Signal()
vactive = Signal()
active = Signal()
generate_en = Signal()
hcounter = Signal(hbits_dyn)
vcounter = Signal(_vbits)
skip = bpc - bpc_phy
self.comb += [
active.eq(hactive & vactive),
If(active,
[getattr(getattr(self.phy.payload, p), c).eq(getattr(getattr(self.pixels.payload, p), c)[skip:])
for p in ["p"+str(i) for i in range(pack_factor)] for c in ["r", "g", "b"]],
self.phy.payload.de.eq(1)
),
generate_en.eq(self.timing.stb & (~active | self.pixels.stb)),
self.pixels.ack.eq(~self.enable | (self.phy.ack & active)),
self.phy.stb.eq(generate_en),
self.busy.eq(generate_en)
]
tp = self.timing.payload
self.sync += [
If(self.enable,
self.timing.ack.eq(0),
If(generate_en & self.phy.ack,
hcounter.eq(hcounter + 1),
If(hcounter == 0, hactive.eq(1)),
If(hcounter == tp.hres, hactive.eq(0)),
If(hcounter == tp.hsync_start, self.phy.payload.hsync.eq(1)),
If(hcounter == tp.hsync_end, self.phy.payload.hsync.eq(0)),
If(hcounter == tp.hscan,
hcounter.eq(0),
If(vcounter == tp.vscan,
vcounter.eq(0),
self.timing.ack.eq(1)
).Else(
vcounter.eq(vcounter + 1)
)
),
If(vcounter == 0, vactive.eq(1)),
If(vcounter == tp.vres, vactive.eq(0)),
If(vcounter == tp.vsync_start, self.phy.payload.vsync.eq(1)),
If(vcounter == tp.vsync_end, self.phy.payload.vsync.eq(0))
)
).Else(
self.timing.ack.eq(1),
hcounter.eq(0),
vcounter.eq(0)
)
]